CN105556367A - Armored optical fiber cable - Google Patents

Abstract

An optical communication cable includes a core, armor surrounding the core, a jacket surrounding and bonded to the armor, and a binder film also surrounding the core and interior to the armor. The core includes buffer tubes surrounding sets of optical fibers and a central strength member. The buffer tubes are stranded around the central strength member in a pattern of stranding including reversals in lay direction of the buffer tubes and the binder film holds the buffer tubes in position. The binder film is bonded to an interior of the armor, thereby providing a quick access capability to access the core via simultaneous removal of the binder film when the armor and jacket are removed.

Description

Armored Fiber Optic Cable

related applications

This application claims U.S. Application No. 61/864,104, filed August 9, 2013, U.S. Application No. 14/099,921, filed December 7, 2013, and U.S. Application No. 14/ 315,872, the content of each said application is the basis of this application and is incorporated herein by reference in its entirety.

background

The present disclosure relates generally to optical communication cables, and more particularly, to optical communication cables that include one or more features configured to protect the cable body from interacting with components positioned within the cable jacket. Optical communication cables have been increasingly used in a wide variety of electronic devices and telecommunications. An optical communication cable may contain or surround one or more communication optical fibers. The cable provides structure and protection for the optical fibers within the cable.

overview

One embodiment of the present disclosure is directed to an optical communication cable comprising a core, an armor surrounding the core, a jacket surrounding and bonded to the armor, and a jacket also surrounding the core and in the armor. Internal binding membrane. The core includes a buffer tube surrounding groups of optical fibers and a central strength member. The buffer tube is stranded around the central strength member in a lay pattern comprising reversals in the lay direction of the buffer tube, and the tie film holds the buffer tube in place . The tie film is bonded to the interior of the armor, thereby providing rapid access capability to the core by removing the tie film at the same time as the armor and sheath are removed.

Additional features and advantages will be set forth in the following detailed description, and in part will be apparent to those skilled in the art from the description or from practice of the embodiment described in the written description and its claims and the accompanying drawings. recognize.

It is to be understood that both the foregoing summary and the following detailed description are exemplary only, and are intended to provide an overview and framework for understanding the nature and character of the claims.

The accompanying drawings are included to provide a further understanding of this specification, and are incorporated in and constitute a part of this specification. The drawings illustrate one or more implementations, and together with the description serve to explain the principles and operations of the various implementations.

Brief description of the drawings

FIG. 1 is a perspective view of a fiber optic cable according to an exemplary embodiment.

2 is a cross-sectional view of the fiber optic cable of FIG. 1 according to an exemplary embodiment.

3 is a detailed cross-sectional view of a portion of the fiber optic cable of FIG. 1 according to an exemplary embodiment.

4 is a cross-sectional view of a fiber optic cable according to another exemplary embodiment.

5 is a perspective view of a fiber optic cable according to an exemplary embodiment.

6 is a cross-sectional view of a fiber optic cable according to another exemplary embodiment.

7 is a cross-sectional view of an armor interface according to another exemplary embodiment.

detail

Referring generally to the drawings, various embodiments of optical communication cables (eg, fiber optic cables, optical fiber cables, etc.) are shown. In general, cable embodiments disclosed herein include a cable jacket or body that is typically formed from a polymeric material (eg, a medium density polyethylene material). A set of optical fibers is surrounded by a protective armor or strengthening material (eg, one or more corrugated sheet metal materials), and a set of armored optical fibers is positioned in the cable jacket central channel. Generally, the cable jacket provides physical support and protection to the optical fibers within the cable, and the armor material provides additional reinforcement to the optical fibers within the cable jacket.

The one or more armor sheets include overlapping portions created by overlapping of opposing edges of the armor material as the armor extends around the optical fiber. The overlapping section and in particular the exposed lateral edges of the upper portion of the overlapping portion may contact the inner surface of the cable jacket, said inner surface defining the channel of the cable jacket. This interaction or contact may tend to cause cracks in the cable jacket, especially when the cable is twisted (such cracks may be referred to in the art as "cable zippering").

The cable jacket embodiments discussed herein include at least one protective member or feature positioned within the wall of the cable jacket that resists or prevents cracking caused by armor overlap from compromising the integrity of the cable jacket. The protective member is positioned adjacent to, and in some embodiments will be in contact with, the overlapping portion of the armor material and/or the exposed lateral edge of the armor. The protective member may serve to resist, limit or prevent crack formation or crack propagation which would otherwise be caused by contact between the armor overlap and the material of the cable sheath.

In some embodiments, the material of the protective member may be more rigid than the main material of the cable jacket. In such embodiments, the discontinuity at the interface of the two dissimilar materials may prevent the crack from propagating further through to the outer surface of the cable jacket. In some other embodiments, the protective member material may be a compliant material that is less rigid than the primary material of the cable jacket. In such embodiments, the protective member may act as a compliant buffer, absorbing movement of the overlapping portions of the armor rather than allowing cracks to form in the primary material of the cable jacket.

In various embodiments discussed herein, the protective member may be formed together with the cable jacket in a single production step. For example, the protective member may be co-extruded with the extrusion material of the cable jacket. In such embodiments, the embedded protective member embodiments discussed herein may obviate the need for additional manufacturing steps to cover or otherwise passivate armor overlapping portions.

Referring to Figures 1 and 2, there is shown an optical communication cable, shown as cable 10, according to an exemplary embodiment. Cable 10 includes a cable jacket, shown as cable jacket 12 , having an inner surface 14 defining a channel, shown as central bore 16 . A plurality of optical transmission elements, shown as optical fibers 18 , are located within bore 16 . In general, cable 10 provides structure and protection to optical fiber 18 during and after installation (eg, protection during handling, protection from elements, protection from vermin, etc.).

In the embodiment shown in FIGS. 1 and 2 , bundles of optical fibers 18 are positioned within a buffer tube 20 . One or more filler rods 22 are also located within bore 16 . Filler rod 22 and buffer tube 20 are arranged around a central support rod 24 formed of a material such as glass reinforced plastic or metal. In some embodiments, a helically wound binder 26 wraps around the buffer tube 20 and filler rod 22 to hold these elements in place around the support rod 24 . A barrier material, such as water barrier 28 , is positioned around the wrapped buffer tube 20 and filler rod 22 . In other embodiments, a membrane binding may be used, which may otherwise be a water barrier.

The armor layer 30 is positioned outside the water barrier 28 or membrane binding. The armor layer 30 extends around the inner components of the cable 10 (including the optical fibers 18 ) such that the armor layer 30 surrounds the optical fibers 18 . Armor layer 30 is substantially all or substantially all of the axial length of cable 10 . The armor layer 30 generally provides an additional layer of protection to the optical fibers 18 within the cable 10 and can resist damage (e.g., damage caused by contact or compression during installation, damage from the elements, damage from rodents, etc. Wait).

As best shown in FIGS. 2 and 3 , the armor layer 30 has a first lateral edge 32 and a second lateral edge 34 . In the illustrated embodiment, the lateral edges 32 and 34 are generally parallel to the longitudinal axes of the cable 10 and optical fiber 18 . Referring to FIGS. 2 and 3 , the armor layer 30 is positioned such that the first lateral edge 32 passes over or overlaps the second lateral edge 34 . In this arrangement, a section 36 of the armor layer 30 adjacent the first lateral edge 32 is positioned above a section 38 of the armor layer 30 adjacent the second lateral edge 34 , thereby forming an overlapping portion 40 . In one embodiment, the upper surface of section 38 is in contact with the lower surface of section 36 such that the thickness T2 (i.e., the dimension in the radial direction shown in FIGS. 2 and 3 ) of overlapping portion 40 is that of armor layer 30. About twice the thickness of the material. With section 38 located below section 36 , upper corner 42 of lateral edge 32 defines the outermost corner of armor layer 30 .

In various embodiments, armor layer 30 may be formed from various strengthening or damage resistant materials. In the embodiment shown in Figure 1, the armor layer 30 is formed from a corrugated sheet metal material having a series of alternating ridges and grooves. The corrugations may be oriented such that the ridges formed thereby are directed away from the longitudinal axis of the cable. In addition, the sheets can be corrugated in a coordinated manner such that overlapping portions of the sheets have intermeshing corrugation features, thereby providing an advantage in both bending the sheets (generally achieved via corrugations) and coupling the sheets to each other via interengagement Instead, provide flexibility to the board. In one embodiment, the corrugated metal is steel. In other embodiments, the corrugated metal may additionally act as a ground conductor for the cable, such as with copper or aluminum armor. In other embodiments, other non-metallic reinforcing materials may be used. For example, armor layer 30 may be formed from fiberglass yarns (eg, coated fiberglass yarns, rovings, etc.). In some embodiments, armor layer 30 may be formed from a plastic material having a modulus of elasticity in excess of 2 GPa, and more specifically in excess of 2.7 GPa. Such an armor layer of plastic may be used to resist animal bites and may contain animal/pest repellent materials (eg, bitter materials, spicy materials, synthetic tiger urine, etc.). In one embodiment, the cable 10 may include a nylon 12 layer for termite resistance.

Referring to FIGS. 2 and 3 , the cable jacket 12 generally includes a primary jacket portion 50 and a secondary jacket portion, shown as a crack-resistant feature 52 . Feature 52 is an elongate member or structure embedded within the material of main jacket portion 50 of cable jacket 12 . In various embodiments, the feature 52 is an abutment member extending the length of the cable jacket 12 between the first and second ends of the cable. In general, main sheath portion 50 is made of a first material and feature 52 is made of a second material different from the first material. Feature 52 includes an inner surface 54 , and feature 52 is positioned such that inner surface 54 may adjoin inner surface 14 of cable jacket 12 such that inner surface 54 and inner surface 14 define channel 16 . In one embodiment, feature 52 is co-extruded along with main sheath portion 50 such that the transition between inner surface 54 and inner surface 14 is a substantially smooth transition.

Feature 52 is positioned within main sheath portion 50 such that inner surface 54 is aligned with, and generally adjacent to, overlapping portion 40, first lateral edge 32, and corner 42 . The feature 52 is aligned with the overlapping portion 40 , the first lateral edge 32 and the corner 42 such that the inner surface 54 is positioned between the overlapping portion 40 and the outer surface 58 of the cable jacket 12 . In the embodiment shown in FIG. 3 , the inner surface 54 of the feature 52 is positioned outside of the overlapping portion 40 , the first lateral edge 32 and the corner 42 (ie, above the orientation of FIG. 3 ). In particular embodiments, the inner surface 54 of the feature 52 is in contact with the outer surface of the overlapping portion 40 and/or the corner 42 of the first lateral edge 32 . In another embodiment, the layer of material of the jacket portion may be positioned between the inner surface 54 of the feature 52 and the outer surface of the overlapping portion 40 and the corner 42 of the first lateral edge 32 . In such embodiments, even if the inner surface 54 is not in direct contact with the overlapping portion 40 due to intervening layers of material, such as when the feature 52 is fully embedded (i.e., fully enclosed when viewed in cross-section) the main sheath portion 50 In some cases, the inner surface 54 can still be positioned at a small distance (for example, less than 1 mm or less than 0.5 mm) from the outer surface of the overlapping portion 40 and the corner 42 of the first lateral edge 32 so as to resist the formation or propagation of cracks ( See eg Figure 8).

The feature 52 serves to resist or prevent crack formation or propagation within the material of the main jacket portion 50 of the cable jacket 12 . In various embodiments, the material of the main sheath portion 50 may be prone to cracking if portions of the armor overlapping portion 40 contact the material of the main sheath portion 50 . Such contact may occur during movement, such as the typical torsional movement during cable installation. However, in the embodiments discussed herein, the features 52 are sized, shaped, positioned, and/or have material properties that allow the features 52 to prevent/limit/resist crack formation or propagation. Thus, by positioning feature 52 adjacent to overlap portion 40 as shown in FIG. 3 , feature 52 is able to interact with overlap portion 40 during movement of cable 10 and resist crack formation/propagation.

In various embodiments, the width W1 (i.e., the circumferential dimension in the circular embodiment of FIG. 40 remains aligned even when rotation of the armor layer 30 relative to the cable jacket 12 occurs during jacket extrusion. In such embodiments, the width W1 of the inner surface 54 of the feature 52 is greater than the width W2 of the overlapping portion 40 . In various embodiments, W1 is between 1 mm and 20 mm and specifically between 3 mm and 10 mm, and W2 is between 2 mm and 10 mm and specifically between 3 mm and 5 mm. In a round cable, the width W1 covers an arc length of at least 2° and/or less than 20°, such as at least 3° and/or less than 15°, around the center of the cable.

The features 52 are positioned such that the features 52 do not always extend from the channel 16 through the main jacket portion 50 to the outer surface 58 of the cable 10 . Thus, the thickness T1 of the feature 52 (ie, the radial dimension of the feature 52 in the circular embodiment of FIG. 2 ) is less than the thickness T4 of the main sheath portion 50 . In this embodiment, feature 52 extends outwardly from channel 16 for a portion of the distance from outer surface 58 such that section 60 of main jacket portion 50 is located between outermost surface 62 of feature 52 and outer cable surface 58 .

In various embodiments, the material of features 52 may be selected relative to the material of main sheath portion 50 to resist/prevent crack formation or propagation. In one embodiment, the modulus of elasticity of the feature 52 may be greater than the modulus of elasticity of the material of the main sheath portion 50 . In this embodiment, feature 52 may be formed from a material having a relatively low bond strength to the material of main sheath portion 50 . In this embodiment, it is believed that the low bond at the interface 56 between the feature 52 and the main sheath portion 50 will inhibit the propagation of cracks that may develop within the material of the feature 52 through interaction with the overlapping portion 40 . By arresting crack propagation at interface 56, the crack cannot extend through outer surface 58 of cable jacket 12, and thus feature 52 acts to keep the wall of cable jacket 12 intact.

In such embodiments, the modulus of elasticity of the material of feature 52 is between 1.0 GPa and 2.0 GPa, specifically between 1.0 GPa and 1.5 GPa, and more specifically about 1.2 GPa. In such embodiments, the material of the main sheath portion 50 has a modulus of elasticity between 100 MPa and 800 MPa, specifically between 0.2 GPa and 0.4 GPa, and more specifically about 0.31 GPa. In various embodiments, the modulus of elasticity of the feature 52 is between 2 and 10 times the modulus of the main sheath portion 50, specifically between 3 and 6 times the modulus of the main sheath portion 50. between, and more precisely between 4 times the modulus of the main sheath portion 50.

In various such embodiments, main jacket portion 50 is formed from an extruded polymeric material, and feature 52 is formed from an extruded polymeric material. In particular embodiments, the main sheath portion 50 is formed from an extruded medium density polyethylene material (eg, a polyethylene material having a density between 0.939 g/cm ³ and 0.951 g/cm ³ ) (eg, comprising extruded medium density polyethylene material, consisting of at least 50% by volume of extruded medium density polyethylene material, comprising extruded medium density polyethylene material as a major component), and feature 52 is composed of extruded polypropylene material formed. In a particular embodiment, feature 52 is formed from an extruded polypropylene material comprising a low percentage of polyethylene. The small amount of polyethylene within the feature 52 provides sufficient bonding to the material of the main jacket portion 50 to allow proper coextrusion of the feature 52 and the main jacket portion 50 while maintaining sufficient dissimilarity and low cohesion to Crack propagation is stopped at interface 56 . In various embodiments, the material of feature 52 may comprise between 2% and 20% polyethylene, specifically between 5% and 15% polyethylene, and more specifically about 9% polyethylene . In such embodiments, these combinations of polyethylene and polypropylene for feature 52 may be used to provide sufficient discontinuity at interface 56 so as to limit crack propagation while providing sufficient separation between the material of feature 52 and the surrounding material. bonding.

In some embodiments, the main sheath portion 50 comprises polyethylene, such as where polyethylene is the main constituent of the main sheath portion 50, such as where the main sheath portion 50 consists essentially (by volume) of polyethylene, Such as greater than 50% by volume polyethylene, at least 70% by volume polyethylene, and the like. In some such embodiments, features 52 are formed from a highly plasticized polymer, such as highly plasticized polyvinyl chloride, polyurethane, polypropylene, or other highly plasticized polymers. The softness and flexibility provided by the plasticizer can moderate crack initiation and crack propagation therefrom. In other embodiments, features 52 are formed from highly filled polymers such as highly filled polyvinyl chloride, polyurethane, polypropylene, or other highly filled polymers. The filler material particles and the interface between the particles and the matrix material can retard or limit crack propagation through the polymer.

In embodiments of the cable 10 in which the modulus of the feature 52 is greater than the modulus of the main jacket portion 50, the thickness of the feature 52 may be less than the thickness of the overlapping portion 40 because in these embodiments, crack propagation is limited by the force at the interface 56. Discontinuous limitation of material. In such embodiments, the thickness T1 (ie, the radial dimension in the circular embodiment of FIG. 3 ) of the feature 52 is between 0.1 mm and 0.5 mm. In such embodiments, the thickness T2 of the overlapping portion 40 is between 0.2 mm and 1.1 mm. In a particular embodiment, the armor layer 30 is formed of a corrugated metallic material and has a thickness T2 between 0.6 mm and 1.2 mm, and more precisely between 0.78 mm and 1.04 mm. In another particular embodiment, the armor layer 30 is formed of a non-corrugated metallic material and has a thickness T2 between 0.2 mm and 0.4 mm, and more precisely between 0.28 mm and 0.34 mm.

In other embodiments, the modulus of elasticity of the feature 52 may be less than the modulus of elasticity of the material of the main sheath portion 50 . In this embodiment, feature 52 may be formed from a compliant material. In this embodiment, it is believed that the compliant material resists or prevents crack formation caused by deformation upon interaction with the overlapping portion 40, thereby acting as a buffer against displacement within the more rigid material of the main sheath portion 50 and the resulting resulting in crack formation.

In such embodiments, the modulus of elasticity of the material of feature 52 is between 10 MPa and 50 MPa, specifically between 15 MPa and 25 MPa, and more specifically between 18 MPa and 19 MPa; Half of the modulus of elasticity of the material of the sheath portion 50, such as not more than one-third of the modulus of elasticity of the material of the main sheath portion 50, such as not more than one-quarter of the modulus of elasticity of the material of the main sheath portion 50 one. In such embodiments, the material of the main sheath portion 50 has a modulus of elasticity between 0.1 GPa and 0.8 GPa, specifically between 0.2 GPa and 0.4 GPa, and more specifically about 0.31 GPa. In various embodiments, main jacket portion 50 is formed from an extruded polymer material, and feature 52 is formed from an extruded polymer material. In a particular embodiment, the main jacket portion 50 is formed from an extruded medium density polyethylene material and the features 52 are formed from an extruded thermoplastic elastomer material (TPE). In one embodiment, the TPE material may be Affinity GA1950, available from The Dow Chemical Company.

In embodiments of the cable 10 in which the modulus of the feature 52 is less than the modulus of the main jacket portion 50, the thickness of the feature 52 may be equal to or greater than the thickness of the overlapping portion 40, because in some such embodiments, the The compliance of ® resists crack formation, such as by the resulting stress isolation. In such embodiments, the thickness T1 of the feature 52 (ie, the radial dimension in the circular embodiment of FIG. 3 is between 0.5 mm and 1.1 mm). In such embodiments, the thickness T2 of the overlapping portion 40 is between 0.2 mm and 1.1 mm. In a particular embodiment, the armor layer 30 is formed of a corrugated metallic material and has a thickness T2 between 0.6 mm and 1.2 mm, and more precisely between 0.78 mm and 1.04 mm. In another particular embodiment, the armor layer 30 is formed of a non-corrugated metallic material and has a thickness T2 between 0.2 mm and 0.4 mm, and more precisely between 0.28 mm and 0.34 mm.

In addition to providing crack resistance via feature 52 , cable jacket 12 may include a plurality of additional elongate members, shown proximate features 70 and 72 . In general, access features 70 and 72 are elongate members or structures embedded within the material of main jacket portion 50 of cable jacket 12 . In various embodiments, the access features 70 and 72 are abutment members that extend the length of the cable jacket 12 between the first and second ends of the cable.

Generally, the main sheath portion 50 is made of a first material, and the access features 70 and 72 are made of a second material different from the first material. The material difference creates a discontinuity or weakening within the cable jacket 12 near the locations of the features 70 and 72 . These discontinuities provide access points that allow a user of cable 10 to tear cable jacket 12 when access to optical fiber 18 is required. In various embodiments, access features 70 and 72 may be formed from a material that has a low degree of cohesion relative to the material of main sheath portion 50 (eg, such as the polypropylene/polyethylene blends discussed above), allowing The user tears the sheath. In various embodiments, the access features 70 and 72 and the anti-crack feature 52 can be formed (e.g., coextruded out).

In various embodiments as shown in FIG. 2, access features 70 and 72 are formed of the same material as feature 52, and access feature 70 adjoins feature 52 such that access feature 70 and feature 52 form an extension of the length of cable 10. A single, continuous elongated member. In this embodiment, proximity feature 70 and feature 52 may be extruded together in a single extrusion process. In this embodiment, outer surface 62 of feature 52 is continuous with outer surface 74 of proximal feature 70 , and section 60 of main sheath portion 50 is located above both outer surface 74 and outer surface 62 . In various embodiments, the thickness T3 of the abutment features 52 and 70 is the distance from the inner surface 54 to the outermost point of the surface 74, and the thickness T4 of the main sheath portion 50 is the distance between the inner surface of the main sheath portion 50 and the outermost point of the surface 74. The distance between the outer surfaces 58. In various embodiments, T3 is at least about 30% of T4 (such as at least one-third) and/or not greater than about 95% of T4 (such as less than the total length) (on average), such as at 50% of T4 and 95%, exactly between 70% and 90% of T4, and more precisely between 80% and 90% of T4. In a specific embodiment, T3 is about 85% of T4.

In various embodiments, the thickness T4 of the main sheath portion 50 is between 0.5 mm and 5 mm, specifically between 1.0 mm and 2.0 mm, and more specifically between 1.0 mm and 1.5 mm. In a particular embodiment, the thickness T4 of the main sheath portion 50 is about 1.3 mm. In such embodiments, the thickness T3 of the abutment features 52 and 70 is between 0.4 mm and 4.5 mm, specifically between 1.0 mm and 1.8 mm, and more specifically between 1.1 mm and 1.5 mm. In a particular embodiment, the thickness T4 of the main jacket portion 50 is about 1.3 mm, and the thickness T3 of the adjoining features 52 and 70 is about 1.1 mm.

In various embodiments, the features 52, 70, and 72 may be formed from a polypropylene/polyethylene blended polymer material as discussed above, and in such embodiments, the main jacket portion 50 may be formed from a medium density polyethylene material form. In such embodiments, low bonding of the material of the adjoining features 52 and 70 to the material of the main sheath portion 50 can be used to limit crack propagation through the interface 56 as discussed above, and the material features 70 and 72 are in contact with the main jacket portion 50 as discussed above. The low cohesion of the material of jacket portion 50 allows jacket 12 to crack.

In other embodiments, access features 70 and 72 may be formed from a first material, and feature 52 may be formed from a second, different material. In one such embodiment, access features 70 and 72 may be formed from a material that has a low degree of cohesion relative to the material of main sheath portion 50 (e.g., a polypropylene/polyethylene blend as discussed above), allowing The sheath is torn by the user, and feature 52 may be formed from a compliant material such as a TPE material. In this embodiment, an interface 78 (shown in phantom in FIG. 3 ) may exist between the anti-crack feature 52 and the access feature 70 .

As shown in FIG. 3 , the width W3 (eg, the largest tangential dimension) of the access feature 70 is less than the width W1 of the inner surface 54 of the crack-resistant feature 52 . In various embodiments, W3 is between 0.1 mm and 0.5 mm, specifically between 0.2 mm and 0.4 mm, and more specifically about 0.3 mm. As discussed above, in various embodiments, W1 is between 1 mm and 20 mm, and specifically between 3 mm and 10 mm, and W2 is between 2 mm and 10 mm, and specifically between 3 mm and 5 mm. In various embodiments, W1 is between 5 and 50 times greater than W3, and specifically between about 10 and 20 times greater than W3.

In the embodiment shown in FIG. 2 , both access feature 70 and anti-crack feature 52 are located at approximately the 12 o'clock position, and access feature 72 is located approximately 180 degrees from feature 70 at the 6 o'clock position. Separating access features 70 and 72 by 180 degrees may allow for maximum access to optical fiber 18 after jacket cracking.

Referring to FIG. 4 , a cable 100 is shown according to an exemplary embodiment. Cable 100 is substantially similar to cable 10, except as discussed herein. Cable 100 includes access features 102 and 104 embedded within the material of main jacket portion 50 . In this embodiment, access features 102 and 104 serve the same function as features 70 and 72 discussed above, except that these access features are spaced apart from feature 52 . In the particular embodiment shown, feature 52 is at the 12 o'clock position, aligned with and adjacent to armor overlap 40, and proximity feature 102 is at the 3 o'clock position approximately 90 degrees clockwise from feature 52 and proximity to feature 104. Located at the 9 o'clock position approximately 270 degrees clockwise from feature 52 .

Referring to FIG. 5 , a cable 110 is shown according to an exemplary embodiment. Cable 110 includes anti-crack feature 52 and access features 70 and 72 within cable jacket 12 and is generally similar to cable 10 except as discussed herein. Cable 110 includes elongate strengthening members (shown as rods 112 ) within cable jacket 12 that extend the length of cable jacket 12 . Rod 112 is formed from a more rigid material than the material of cable jacket 12 . In various embodiments, the strengthening member is metal, braided steel, glass reinforced plastic, fiberglass, fiberglass yarn, or other suitable material. The cable 110 includes a stack 114 of a plurality of optical transmission elements, shown as fiber optic ribbons 116 , within the channel of the cable jacket 12 .

Referring to FIG. 6 , a cable 120 is shown according to an exemplary embodiment. Cable 120 is substantially similar to cable 10, except as discussed herein. Cable 120 includes two anti-crack features 52 and two access features 70 adjacent to each feature 52 . In the illustrated embodiment, the cable 120 includes a two-part armor layer 122 (eg, a clamshell armor layer) that includes two overlapping armor portions 40 . The anti-crack feature 52 and the access feature 70 are positioned adjacent to the overlapping portion 40 . In this embodiment, the armor layer 122 includes a first section 124 and a second section 126 . In the illustrated embodiment, the first section 124 and the second section 126 are semi-cylindrical or arcuate elements, wherein the second section 126 is partially received within the first section 124 , thereby creating the overlapping portion 40 . In other embodiments, the first section may be outside the second section on one side and vice versa on the other side. The use of two anti-crack features 52 may also cause the sheath to tear at the section between the two anti-crack features to facilitate access to the contents of the cable 120 .

In this embodiment, both access features 70 are positioned in alignment with overlapping section 40 . This positioning allows the cable jacket 12 to be opened and at the same time or with the same opening action that opens the cable jacket 12 to allow the armor layer 122 to be opened (e.g., by separating the first armor section 124 from the second armor section 126 ).

In some such embodiments, binders (e.g., chemical binders such as maleic anhydride, ethylene acrylic acid copolymer; flame treatment to alter surface chemistry; surface roughening to increase surface area) may be used in the cable jacket 12 or used to connect with the cable sheath 12, so as to increase the connection between the inner surface of the cable sheath 12 and the outer surface of the armor layer 122, one or both of the first section 124 and the second section 125 and the sheath bonding between sets. The bond between the cable jacket 12 and the armor layer 122 may facilitate removal of both layers together with a single opening action. The adhesive may additionally be used to prevent relative sliding of the edges of the two-piece armor layer 122, and the adhesive may also be used to prevent relative sliding of components of any of the other embodiments disclosed herein. The adhesive can be mixed into the primary sheath material, positioned on the armor surface, or both.

In one embodiment, the cable 120 includes a binding layer, shown as a film binding 128 , positioned around the buffer tube 20 . In general, film binder 128 is a layer of material that surrounds and is bonded to buffer tube 20 within central channel 16 . In one embodiment, the cable 120 and/or film binder 128 may be a binder/cable as disclosed in U.S. Application Serial No. 13/790,329, filed March 8, 2013, which is incorporated by reference in its entirety. way incorporated into this article. In some embodiments, the outer surface of the binding 128 is bonded to the inner surface of the armor layer 122 (e.g., with glue, adhesive, chemical bonding) so that the access feature 70 can be used to The cable jacket 12, armor 122, and binder 128 are torn in a single tearing action to gain access to the contents of the cable 120 (e.g., buffer tubes 20 for optical fibers 18, stacks of optical fiber ribbons, bundled buffered optical fibers, or other arrangements). The tie-down film 128 may also serve as a carrier of water-blocking material, such as SAP partially embedded on the inside surface of the film 128 . The tie film 128 is generally thinner than the sheath, such as less than one-fifth, less than one-tenth, or even less than one-twentieth that of the sheath 12 . The tie film 128 may be extruded and may include polyethylene, polypropylene, or another polymer as its main constituent. The tension in the tie film 128 may hold the contents of the core together as the tie film 128 cools and shrinks after extrusion. In other embodiments, the tie film 128 is not bonded to the armor.

In the embodiments discussed above, the main jacket portion 50 is formed from a single layer of extruded polymeric material (e.g., a medium density polyethylene material), and in other embodiments, the jacket 12 may comprise multiple layers of material. . In various embodiments, the main sheath portion 50 can be of various materials used in cable manufacture, such as polyvinyl chloride (PVC), polyvinylidene fluoride (PVDF), nylon, polyester or polycarbonate and their of copolymers. Additionally, the material of the main jacket portion 50 may include small amounts of other materials or fillers that provide different properties to the material of the main jacket portion 50 . For example, the material of the main sheath portion 50 may include materials that provide for coloring, UV/light blocking (eg, carbon black), burn resistance, and the like.

Referring now to FIG. 7 , the interface 210 between the lateral edges 214 , 216 of the armor 212 is shown. The lateral edges 214, 216 may be from the same armor plate (see generally FIG. 2 ), or from separate armor plates (see generally FIG. 6 ). According to an exemplary embodiment, interface 210 includes a seat 218 in which one of lateral edges 216 is retained. Sheath 220 retains lateral edge 216 in seat 218 during operation of the corresponding cable. However, the standoff 218 also allows the lateral edge 216 to be withdrawn from the standoff 218 (perpendicularly as shown in FIG. 7 ), such as where resistance from the standoff 218 itself is minimal (e.g., less than 15N per meter of length). Withdrawing, such as by pulling the sheath 220 away from the interior, wherein the lateral edges are drawn apart in opposite directions tangential to the interface. In other words, the standoff 218 can lock the lateral edges 214, 216 together with certain degrees of freedom, such as against relative rotation, relative radial translation (radial translation in the horizontal direction of FIG. 7 ), and relative longitudinal translation ( Translation into and out of FIG. 7 is limited via alignment corrugations between the upper shroud sheets of armor 212 ), but relatively tangential translation (ie, pulled apart in the vertical direction of FIG. 7 ) may be permitted.

In such embodiments, the interface 210 can also be aligned with tear features and/or anti-zipper features 222 in the sheath 220 to mitigate inadvertent zip tears The possibility of and/or can also facilitate the intentional tearing of the sheath 220. The net force pulling the jacket 220 and armor 212 apart may be less than 80N to initiate a tear through the jacket 220 along the tear feature and/or anti-zip tear feature 222 on the free end of the cable. As shown in FIG. 7 , visual and/or tactile markings on the exterior of a corresponding cable (eg, either of FIGS. 2 and 6 ) may assist a user in locating interface 210 . The markings may include raised portions 224 of the sheath 220 , such as bumps or elongated ridges on the sheath 220 .

While the specific cable embodiments discussed herein and shown in the drawings primarily relate to cables having a generally circular cross-sectional shape defining a generally cylindrical internal lumen, in other embodiments Among other things, the cables discussed herein can have any number of cross-sectional shapes. For example, in various embodiments, the cable jacket 12 may have a square, rectangular, triangular, or other polygonal cross-sectional shape. In such embodiments, the cable channel or hole may be the same shape as the cable jacket 12 or a different shape. In some embodiments, the cable jacket 12 may define more than one channel. In such embodiments, the multiple channels may be the same size and shape as each other, or each channel may be a different size or shape.

The optical fibers discussed herein may be flexible, transparent optical fibers made of glass and/or plastic. An optical fiber can be used as a waveguide to transmit light between the two ends of the fiber. Optical fibers may include a transparent core surrounded by a transparent cladding material having a lower refractive index. Light can be kept in the core by total internal reflection. Glass optical fibers may contain silica, but some other materials such as fluorozirconate, fluoroaluminate and chalcogenide glasses as well as crystalline materials such as sapphire may also be used. Light can be guided down the core of the fiber by an optical cladding with a lower refractive index, which traps the light in the core by total internal reflection. The cladding may be coated with a buffer and/or another coating that protects the cladding from moisture and/or physical damage. These coatings can be UV curable urethane acrylate composites that are applied to the outside of the fiber during the drawing process. The coating protects the strands of glass fiber. In some contemplated embodiments, the jackets and armors disclosed herein may be used with electrical cables and conduits, such as pipes or conductive copper bearing cables, which may not include optical fibers.

It is in no way intended that any method set forth herein be construed as requiring performance of the steps of the method in a particular order, unless expressly stated otherwise. Thus, where the method claims do not actually recite the order in which the method steps are to be followed, or where the claims or specification do not otherwise specifically state that the steps are to be limited to a specific order, no inference is intended to be made as to any particular order.

It will be apparent to those skilled in the art that various modifications and changes can be made without departing from the spirit or scope of the disclosed embodiments. Since those skilled in the art can conceive of modified combinations, subcombinations and variations of the embodiments that incorporate the spirit and substance of the disclosed embodiments, the disclosed embodiments should be construed to include the appended claims and their Anything within the range of equivalents.

***

As noted above, the cable 120 and/or film binder 128 may be a cable/bundle as disclosed in U.S. Application Serial No. 13/790,329, filed March 8, 2013, which is incorporated by reference in its entirety and into this article. In one embodiment, a fiber optic cable includes a core and a binding film. The core includes a central strength member and a core element, such as a buffer tube housing an optical fiber, wherein the core elements are stranded around the central strength member in a stranding pattern comprising a reversal in the direction of lay of the core element. The tie film is under radial tension around the core such that the tie film resists outward lateral deflection of the core elements. Additionally, the tie film loads the core element vertically to the central strength member such that contact between the element and the central strength member provides a coupling between the two, thereby limiting axial migration of the core element relative to the central strength member.

The cable 120 may be an outside loose tube cable, an indoor cable with fire/flame retardant properties, an indoor/outdoor cable, or another type of cable, such as a data center interconnect cable with micromodules or a hybrid fiber optic cable that includes conductive elements. According to an exemplary embodiment, the cable 120 includes (eg, subassemblies, micromodules), may be located in the center or otherwise of the cable 120 , and may be the only core or one of several cores of the cable 120 . According to an exemplary embodiment, the core of the cable 110 includes a core element. The core element of the cable 120 includes a tube, such as a buffer tube 20 surrounding at least one optical fiber 18, a tight-buffer or other tube surrounding an optical fiber. According to an exemplary embodiment, tube 20 may contain two, four, six, twelve, twenty-four, or other numbers of optical fibers 18 . In contemplated embodiments, the core element of the cable 120 additionally or alternatively includes a tube 20 in the form of a dielectric insulator surrounding the conductive wire or wires, such as in the case of a hybrid cable.

In some embodiments, tube 20 further includes a water blocking element, such as a gel (eg, grease, petroleum-based gel) or an absorbent polymer (eg, superabsorbent polymer particles or powder). In some such embodiments, the tubes 20 comprise yarns carrying (e.g., dip-coated) superabsorbent polymers, such as each tube 20 comprising at least one water-blocking yarn, at least two such yarns, or at least four such yarns. such yarns. In other contemplated embodiments, tube 20 includes superabsorbent polymer without a separate carrier, such as where the superabsorbent polymer is loose or attached to the inner wall of tube 20 . In some such embodiments, the particles of superabsorbent polymer are partially embedded in the walls of tube 20 (inner and/or outer walls of the tube) or bonded to the tube with an adhesive. For example, particles of superabsorbent polymer may be pneumatically sprayed onto the wall of tube 20 and embedded in tube 20 during extrusion of tube 20 while tube 20 is viscous, such as a tube from an extrusion process. According to an exemplary embodiment, the optical fibers 18 of the tube 20 are glass optical fibers having an optical fiber core surrounded by a cladding. Some such glass optical fibers may also include one or more polymer coatings. The optical fibers 18 of the tube 20 are single-mode optical fibers in some embodiments, multi-mode optical fibers in other embodiments, and multi-core optical fibers in other embodiments. Optical fiber 18 is bend-resistant (eg, a bend-insensitive optical fiber such as CLEARCURVE ^™ optical fiber manufactured by Corning Incorporated, Corning, NY). Optical fiber 18 may be a colored optical fiber and/or a tight-buffered optical fiber. Optical fiber 18 may be one of several optical fibers aligned and bound together in a fiber optic ribbon.

According to an exemplary embodiment, in addition to the tube 20, the core of the cable 120 includes a plurality of additional core elements (e.g., elongated elements extending longitudinally through the cable 120), such as at least three additional core elements, at least five additional core elements element. According to an exemplary embodiment, the plurality of further core elements comprises at least one of a filler rod and/or another tube 20'. In other contemplated embodiments, the core element of cable 120 may also or instead include straight or stranded conductive wire (eg, copper or aluminum wire) or other elements. In some embodiments, the core elements are all about the same size and cross-sectional shape (see FIG. 6 ), such as all circular, and have a diameter within 10% of the diameter of the largest of the core elements of the cable 120 . In other embodiments, the core element of cable 120 may vary in size and/or shape.

As noted above, the cable 120 includes a binding film 128 (eg, a film) surrounding the core of the cable 120 , the binding film 128 being on the exterior of some or all of the core elements of the cable 120 . The tube 20 and any additional core elements are at least partially constrained (ie held in place) and are bound to each other either directly or indirectly by the tie film 128 . In some embodiments, the tie film 128 directly contacts the core element of the cable 120 . For example, tension (eg, hoop tension) in tie film 128 may hold the core elements against central strength member 24 and/or against each other. Loading of the tie film 128 may further increase interfacial loading (eg, friction) between the core elements relative to each other and relative to other components of the cable 120 , thereby constraining the core elements of the cable 120 . According to an exemplary embodiment, the tie film 128 includes (eg, is formed of, consists essentially of, has an amount of) a polymeric material such as polyethylene (eg, low density polyethylene, medium density polyethylene ethylene, high-density polyethylene), polypropylene, polyurethane, or other polymers. In some embodiments, tie film 128 includes at least 70% by weight polyethylene, and may further include stabilizers, nucleating initiators, fillers, flame retardant additives, reinforcing elements (e.g., chopped glass fibers), and/or or some or all of such additional components or combinations of other components.

According to an exemplary embodiment, the binding film 128 is formed of a material having a Young's modulus of 3 gigapascals (GPa) or less, thereby providing the binding film 128 with a relatively high elasticity or spring force so that the binding film 128 The shape of the core element can be conformed without undue twisting of the core element, thereby reducing the possibility of attenuation of the optical fiber 18 corresponding to the core element. In other embodiments, the tie film 128 is formed from a material having a Young's modulus of 5 GPa or less, 2 GPa or less, or a different elasticity, which may not be relatively high. According to an exemplary embodiment, the tie film 128 is thin, such as 0.5 mm thick or less (eg, about 20 mil thick or less, where "mil" is 1/1000 inch). In some such embodiments, the film 128 is 0.2 mm or less (eg, about 8 mils or less), such as greater than 0.05 mm and/or less than 0.15 mm. In some embodiments, the tie film 128 has a thickness in the range of 0.4 mils to 6 mils, or another thickness. In contemplated embodiments, the thickness of the film may be greater than 0.5 mm and/or less than 1.0 mm. In some cases, for example, tie film 128 has an approximately typical garbage bag thickness. The thickness of the binding film 128 may be less than one-tenth of the largest cross-sectional dimension of the cable, such as less than one-twentieth, less than one-fiftieth, less than one-hundredth, while in other embodiments, the binding The membrane 128 may additionally be sized relative to the cable cross-section. In some embodiments, the sheath 12 is thicker than the tie film 128 when comparing average cross-sectional thicknesses, such as at least twice the thickness of the tie film 128, at least ten times the thickness of the tie film 128, at least The tie film 128 is at least twenty times thicker. In other contemplated embodiments, sheath 12 may be thinner than tie film 128, such as a 0.4 mm nylon skin sheath extruded over a 0.5 mm tie film.

The thickness of the tie film 128 may not be uniform around the bound twisted elements of the cable 120 . Applicants have discovered that the material of the tie film 128 undergoes some migration during manufacture. For example, the belts (treads, tracks) of a caterpillar are used to apply a compressive force to the tie membrane 128 as the tie membrane 128 solidifies and contracts to hold the stranded core elements to the central strength member 24, The tie film 128 can thus be slightly flattened on the opposite side of the tie film 128 . Thus, as used herein, the "thickness" of the tie film 128 is the average thickness around the perimeter of the cross-section. For example, the slightly flattened portion of tie film 128 caused by the crawler may be at least 20% thinner than the interfaced portion of tie film 128 and/or the average thickness of tie film 128 .

The use of a relatively thin tie film 128 allows for rapid cooling (e.g., on the order of milliseconds) of the tie film 128 during manufacture, and thereby allows the tie film 128 to quickly hold the core elements of the cable 120 in place, such as Maintaining a specific strand configuration facilitates manufacturing. In contrast, the cooling may be too slow to prevent movement of the stranded core elements when: when a full sheath or conventional sheath is extruded over the core without utilizing a binding yarn (or binding film); or Even when relatively thin films are extruded without the use of a caterpillar (sometimes referred to as a "caterpillar") or other auxiliary devices. However, in some embodiments, it is contemplated that such cables include the technologies disclosed herein (eg, co-extruded proximity features, embedded water-swellable powders, etc.). After applying the tie film 128 , the manufacturing process may further include applying a thicker sheath 12 to the outside of the tie film 128 to increase the robustness and/or weatherability of the cable 120 . In other contemplated embodiments, the core of cable 120, ie, the core surrounded by tie film 128, may be used and/or sold as a finished product.

As shown in Figures 1 and 6, the cable 120 further includes a central strength member 24, which may be a dielectric strength member, such as a jacketed glass reinforced composite rod. In other embodiments, the central strength member 24 can be or include steel rods, stranded steel, drawn yarns or fibers (eg, bundled aramid), or other reinforcing materials. In one embodiment, the central strength member 24 comprises a central rod and is sheathed with a polymeric material (eg, polyethylene, low smoke zero halogen polymer).

According to an exemplary embodiment, powder particles (such as superabsorbent polymer and/or another powder (eg, talc)) or another water-absorbing component (eg, water-blocking tape, water-blocking yarn) are attached to the central strength member 24 on the outer surface. At least some of the powder particles may be partially embedded in the jacket of the central strength member 24 and attached to the jacket by pneumatically spraying the particles with the jacket while the jacket is in a viscous and/or softened state. The powder particles may increase or otherwise affect the coupling between the central strength member 24 and the core elements of the cable 120 surrounding the central strength member 24 .

Alternatively or in addition thereto, the particles may be attached to the jacket of the central strength member 24 using an adhesive. In some embodiments, the central strength member 24 comprises an unjacketed rod, and particles may adhere to the unjacketed rod. In contemplated embodiments, a strength member such as a glass reinforcing rod or an upper-jacketed steel rod includes superabsorbent polymer or other particles attached to its outer surface, as disclosed above, without the strength member needing to be a central strength member.

In some embodiments, the core elements of the cable 120 are stranded (ie, wound) around the central strength member 24 . The core elements of the cable 120 may repeat a reverse wobble pattern, such as a so-called S-Z lay (see generally FIG. 1 ), or be stranded in other lay patterns (eg, helical). Bound film 128 may constrain the core elements of cable 120 into a stranded configuration, thereby facilitating mid-span or cable end proximity of optical fibers 18 and cable bending without being induced by outward expansion from the approach location or bending in the core of cable 120. The core element releases tension.

In other contemplated embodiments, the core elements of cable 120 are unstranded. In some such embodiments, the core elements of the cable 120 include micromodules or tight-buffered optical fibers oriented generally parallel to each other within the binding film 128 . For example, a harness cable and/or interconnect cable may include a plurality of micromodules, each including an optical fiber and a drawn yarn (eg, aramid), wherein the micromodules are bound together by a binding film 128 . Some such cables may not include a central strength member. Some embodiments include multiple cores or subassemblies, each bound by a tie film 128 and nested together in the same carrier/distribution cable, possibly bound together with another tie film. For some such embodiments, the techniques disclosed herein for rapid cooling/solidification during extrusion and inducing radial tension in the tie film 128 for coupling to the central strength member 24 are useful for manufacturing May be unnecessary.

In some embodiments, the binding film 128 of the cable 120 includes powder particles that may be used to provide water resistance and/or to control the coupling (eg, detachment) of mating surfaces in the cable 120 . In some embodiments, the powder particles have an average largest cross-sectional dimension of 500 micrometers (μm) or less, such as 250 μm or less, 100 μm or less. Thus, the particles may be larger than water blocking particles that may be used within the tube 20, impregnated into the yarn, or embedded in the inner wall of the tube 20 as disclosed above to moderate fiber microbend attenuation, which may be Has an average largest cross-sectional dimension of less than 75 μm.

In some embodiments, at least some of the powder particles are directly or indirectly coupled to (e.g., directly attached to, adhered to, in contact with) the binder film binding film 128, such as coupled to an adhesive film. The surface of the adhesive film binding film 128, the outer surface coupled to the adhesive film binding film 128, the outer surface coupled to the adhesive film binding film 128, and/or the outer surface of the adhesive film binding film 128 inner surface. According to an exemplary embodiment, at least some of the powder particles are partially embedded in the adhesive film binding film 128, such as partially through the surrounding surface plane of the adhesive film binding film 128, while being partially away from the adhesive film binding film. The surface of 128 protrudes; or in other words, makes its part submerged in the adhesive film binding film 128, while its other part is exposed. In some embodiments, a rotating die can be used to increase the normal force on the tube.

The powder particles can be attached to the binding film 128 by pneumatically spraying the powder particles onto the binding film 128, inside and outside the associated extrusion cone formed during extrusion of the binding film 128. Pneumatic spraying can also Rapid cooling of the binding film 128 is facilitated. In other embodiments, electrostatic or other means may be used to encourage powder particles to embed or otherwise couple to the binding film 128 . In other embodiments, glue or other attachment means are used to attach the powder particles to the tie film 128 . The use of the tie film 128 as a carrier for the superabsorbent polymer particles can eliminate the need for water blocking tape between the core and the cable components outside the core, as well as binding to hold the water blocking tape in place yarn needs. In other embodiments, powder particles may be present but loose and/or not attached to the tie film 128 . In contemplated embodiments, tie film 128 may be coated with a continuous water blocking material/layer, or may include other types of water blocking elements or may not include water blocking elements.

According to an exemplary embodiment, the powder particles include superabsorbent polymer particles, and the amount of superabsorbent polymer particles is is less than 100 grams per square meter (g/m ² ). In some such embodiments, the amount of superabsorbent polymer particles is between 20 g/m ² and 60 g/m ² , such as between 25 g/m ² and 40 g/m ² . According to an exemplary embodiment, the amount of superabsorbent polymer or other water-blocking element used in the cable is at least sufficient to block a one-meter head of tap water in a one-meter length of cable 120 according to an industry standard water penetration test, which may correspond to In addition to the above quantities, it depends on other characteristics of the cable 120, such as the gap spacing between the core elements.

According to an exemplary embodiment, at least some of the powder particles are located on an inner surface of the binding film 128 between the binding film 128 and the core element of the cable 120 . In addition to blocking water, this placement can relieve the tie film 128 during manufacture of the cable 120, such as if the tie film 128 is tacky from extrusion or other manufacturing methods such as laser welding or heat softening. Adhesion to the core element. Alternatively or in combination, in some embodiments at least some of the powder particles are positioned on the outer surface of the binding film 128 .

The powder particles located on the outer surface of the binding film 128 may be on the binding film 128 and the components of the cable 120 outside the binding film, such as the metal or dielectric armor 30 ( FIG. 1 ) or the micromodule outside the core of the cable 120 . ) to achieve water blocking. As shown in FIG. 1, armor 30 may be corrugated steel or another metal, and may also serve as a ground conductor, such as is the case for hybrid fiber optic cables having the features disclosed herein. The use of film binders instead of thicker layers allows for narrower "light armor" designs where there is no jacket between the armor 30 and the core of the cable. Alternatively, armor 30 may be a dielectric, such as formed from a tough polymer (eg, some forms of polyvinyl chloride).

According to an exemplary embodiment, an embedded material discontinuity (such as an accessible feature 70 in the sheath 12, such as a narrow strip of coextruded polypropylene embedded in the polyethylene sheath 12) may provide a tear path to facilitate sheathing. Set of 12 is opened. Alternatively, a ripcord in or attached to the sheath 12 may cause the sheath 12 to open.

In some embodiments, sheath 12 and tie film 128 may be blended together during extrusion of sheath 12 onto tie film 128, particularly where sheath 12 and tie film 128 are formed of the same material and There are no powder particles in between. In other embodiments, the jacket 12 and the binding film 128 may remain separated from each other or at least partially separated such that when the cable 120 is viewed in cross-section, the jacket and the binding film are each visually distinct. is distinguishable. In some embodiments, the tie film 128 and the sheath 12 are not colored the same as each other. For example, they may be colored in visually distinguishable colors having a "color value" difference of at least 3 on the Munsell scale. For example, jacket 12 can be black and tie film 128 can be white or yellow, but both include polyethylene (eg, consist essentially of polyethylene, consist of at least 70% by weight polyethylene).

In some contemplated embodiments, sheath 12 is opaque, such as colored in black and/or includes UV light blocking additives, such as carbon black; however, tie film 128 is translucent and/or a "natural" colored polymer There is no added color such that less than 95% of visible light is reflected or absorbed by the tie film 128 . Accordingly, in at least some such embodiments, when the jacket 12 is opened or stripped away from the bundle film 128 and the core of the cable 120, at least some of the tube 20 and the plurality of additional core elements may at least partially penetrate the bundle. Membrane 128 sees while being bound by the tie-down film, where tie-down film 128 is unopened and left intact, such as light from a 25 watt white light bulb at 20 degrees in a room that is not otherwise lit. This can be seen when the beam is directed directly onto the tie film 128 from a distance of one meter or less. In contemplated embodiments, the core includes a tape or string (eg, a polymeric ripcord) positioned beneath and visible through the tie film 128, which may include an inner lining about the core. inclusions or specific locations along the length of the cable 120.

According to an exemplary embodiment, the binding membrane 128 is continuous circumferentially around the core such that it forms a continuous closed loop (e.g., a closed tube) when viewed in cross-section, such as shown in FIG. 6; and also Continuous in the longitudinal direction along the length of the cable 120, wherein the length of the cable 120 is at least 10 meters (m), such as at least 100 m, at least 1000 m; and may be stored on large spools. In other contemplated embodiments, the cable 120 is less than 10 m in length.

In some embodiments, the tie-down film 128 takes the shape of contiguous core elements around its cross-sectional perimeter and extends in a generally straight path over the spaces between the core elements, in some embodiments , which can result in a generally polygonal shape of the tie film 128 with rounded vertices, where the number of sides of the polygon corresponds to the number of contiguous core elements.

In some embodiments, the tie film 128 is arc bent into the spaces between the core elements such that the tie film 128 does not extend tangentially between the adjoining core elements, but instead surrounds the perimeter and the stranded core elements. The interspace undulates between concave and convex arcs. The concave arc may not be a perfect arc, but may instead have an average radius of curvature greater than the radius of one or all of the stranded core elements and/or the central strength member 24 . In other words, the concavity of the concave arc is smaller than the convexity of the convex arc. Applicant theorizes that the undulations between the concave and convex arcs constrain the stranded core elements, thereby resisting unwinding of the stranded core elements around the central strength member 24 . Applying a vacuum to the interior of the extrusion cone used to form the tie film 128 can increase the drawdown rate of the extrudate and can promote concave arc formation. Applicants further believe that the undulations and concave arcs increase the torsional stiffness of the tie membrane 128 .

The use of the continuous tie film 128 blocks water from reaching the core of the cable 120 . In other embodiments, the tie film 128 includes pinholes or other openings. In some contemplated embodiments, the tie film may be extruded in a criss-cross grid pattern of film strips, or as helical or counter-helical tie film strips, such as through a rotating crosshead or spinneret. Either the core or the crosshead may rotate, and the core may rotate at a different rate than the crosshead, or vice versa. In other contemplated embodiments, a pre-formed crimp or C-shaped tube may be used as the binder 128 by which the core is bound.

In some embodiments, the tie film 128 is in tension around the core of the cable 120, wherein the hoop stress spreads relatively uniformly around the lateral (i.e., cross-sectional) perimeter of the tie film 128, wherein the tie film 128 covers (e.g., directly or indirectly contact) elements of the core of the cable 120 . Thus, the binding membrane 128 resists outward lateral deflection of the core element relative to the rest of the cable 120, such as outward torsional spring force of an S-Z stranded core element, buckling of a non-stranded core element such as a flat fiberglass yarn. deflection, or other loads. Thus, tension in the tie film 128 may increase cable stability and integrity, such as improvements achieved in compression of the cable 120 . In one embodiment, the tie film 128 is capable of cooling and shrinking to the extent that a load is applied to the stranded core elements of the cable 120, thereby compressing the core elements (e.g., the buffer tube 20) against the central strength member 24, thereby provide coupling between them.

In some embodiments, the tension of the binding film 128 has a distributed load of at least 5 Newtons (N) per meter (m) of length of the cable 120, which can be measured by measuring the entire binding film 128 surrounding the core element The average diameter of the tie film 128 is then opened, the core element is removed, the tie film 128 has time (for example, at least one day, depending on the material) to shrink to an unstressed state at a constant temperature, and the tie film is measured 128 A reduction in the lateral dimension (ie, compared to the average perimeter). Tension is the load required to stretch the tie film 128 to its original width.

In various embodiments, thermoplastics and/or materials other than polyethylene may be used to form the tie film 128 . The tie film 128 can be of various colors and can have a UV stabilizer that allows the tie film 128 to be the exterior of the finished outdoor product. Thereafter, the tie film 128 may be printed. Tie film 128 may include tearable or accessible features, such as those disclosed herein with respect to sheath 12 . In some embodiments, the tie film 128 may surround a wide variety of different types of stranded cable components, such as S-Z stranded tight buffer fibers, filler rods, fiberglass yarns, aramid yarns, and other components. According to an exemplary embodiment, cable 120 includes a dielectric armor layer, such as armor 30 , under jacket 12 between jacket 12 and a core element of cable 120 .

According to an exemplary embodiment, the material of the binding film 128 may be selected such that the melting temperature of the material of the binding film 128 is less than (eg, at least 30° C. less, at least 50° C. less) than the extrusion temperature of the sheath 12 (e.g., about 200-230° C.±20° C.), the sheath is then extruded onto the tie film 128 . In some such embodiments, the tie film 128 is melted or blended into the sheath 12 . In other embodiments, the tie film 128 is maintained separate from the sheath 12 by an intermediate material, such as superabsorbent polymer particles. The reason why the stranded core elements of the cable 120 do not migrate axially or outwardly during the extrusion of the sheath 12, upon melting or softening of the binding film 128, is the applicant's reasoning as follows: When extruding (for example, at least 2 seconds, at least 5 seconds, at least 10 minutes after stranding and applying the tie film 128), the stranded core elements of the cable 120 are sufficiently compatible with the stress relaxation of the material of the stranded core elements. The geometry of the stranding pattern conforms so as to reduce the spring force initially carried by the stranding elements when stranding; and applicant theorizes that the sheath 12 actively contributes to the radial tension applied by the tie-down membrane 128 to constrain the core elements and load them vertically onto the central strength member 24.

Additionally, applicants have discovered that applying the tie film 128 at extrusion temperatures above the melting temperature of the stranded core elements (eg, at least 30°C above, at least 50°C above) does not melt or substantially deform the stranded elements. Thus, the tie film 128 may comprise the same or a similar molten polymer as the buffer tube 20 twisted in the core, such as polypropylene. Additionally, applicants have found that there is little or no sticking between the tie film 128 and the buffer tube 20 twisted in the core of the cable 120 .

In addition, applicants have discovered that the greater strength of polypropylene relative to polyethylene allows the tie film 128 to be thinner for the purpose of providing the same amount of coupling force between the stranded core elements and the central strength member 24. Polypropylene tie film 128 . For example, it was found that a 0.15mm tie film 128 of polyethylene has a radial force of about 70N, while a 0.15mm tie film 128 of polypropylene has a radial force of about 85N. However, polyethylene is generally significantly less expensive than polypropylene, and in other embodiments, polyethylene may be used for the tie film 128 .

In some embodiments, tie film 128 is formed from a first material and sheath 12 is formed from a second material. The second material of sheath 12 may comprise (such as consist essentially of (>50% by weight)) a first polymer, such as polyethylene or polyvinyl chloride; and the first material of tie film 128 may comprise (such as consist essentially of) the first polymer Dipolymers, such as polypropylene. In some embodiments, the first material further comprises a first polymer (e.g., at least 2%, at least 5%, at least 10%, and/or less than 50%, such as less than 30%, by weight of the first material) . In addition to primarily including the second polymer in the first material, inclusion of the first polymer in the first material of the tie film 128 promotes bonding between the first material and the second material so that the tie film 128 can be coupled to the jacket 12, and when the jacket 12 is removed from the core of the cable 120, such as when the jacket is removed at a mid-span access location, the tie film can be removed from the core Automatically removed.

Using pull-through testing, applicants have found that the tie film 128 as disclosed herein produces at least 10N for a stranded element of 100mm length between the stranded core element of the cable 120 and the central strength member 24 A (net) static friction force of , such as a (net) static friction force of at least 15N. Through pull-through testing, applicants have found that the magnitude of the static friction force is related to the thickness of the tie film 128 . For a polypropylene tie film 128 having an average wall thickness of at least 0.02mm but less than 0.04mm, the static friction force of a 100mm section of the stranded core element (excluding the sheath) is at least 10N, such as about 12.4N, and and/or the average static friction force of a 200mm section of the stranded core element is at least 20N, such as about 23.1N. Therefore, for such a tie film 128, the reverse oscillating stranding pattern must be such that the net spring force of the stranded core element is about 10N or less for a 100mm segment to prevent twisting during manufacture. Axial migration of core elements and "bird's nest" formation. Applicants have also found that for a polypropylene tie film 128 having an average wall thickness of at least 0.08mm but less than 0.15mm, the average static friction force of a 100mm section of the stranding element is at least 20N, such as about 30N, and/or stranding The average static friction force of a 200mm section of the coupling element is at least 40N, such as about 50N. Some tests included stranding elements bound by both the binding membrane 128 and the binding yarn in order to determine the effect of the binding membrane 128 .

In some embodiments, a stranded core of a cable, such as cable 120, includes a binding film 128 that constrains the core elements with reversed stranding. In some embodiments, the core can be enclosed within a sheath (such as sheath 12). Tie film 128 is a thin polymer material (eg, polypropylene, polyethylene) that can be torn and peeled by hand to provide access to the stranded core elements and central strength member 24 . Once released from the tie film 128 , the stranded core elements can be disengaged from the central strength member 24 .

In some embodiments, another advantage of the tie film 128 is that the stranded core elements can be accessed by opening the tie film 128 without cutting and/or removing longitudinal tension in the tie film 128 . For example, longitudinal cuts are formed in the tie film 128 that can be guided through the spaces (ie, open spaces, gaps, grooves) between the stranded core elements. Due to the thinness of the tie film 128, the incisions can be made without the use of special tools. For example, the cuts in the tie film 128 can be cut with scissors. A razor, wedge, pocketknife, or other commonly used tools will also work. Longitudinal cuts in the tie film 128 provide openings through which the stranded core elements can be unwound in a reversible fashion, thereby providing additional length for manipulating the stranded elements, and one or more of the elements can be separated at the mid-span position. catch. For example, the buffer tube 20 may be cut and pulled through the opening formed by the cut in the tie film 128 to allow access to the optical fiber 18 . At the same time, the remainder of the tie film 128 is held together and maintains tension along the length of the cable 120 at the front and rear of the cut. Once access is no longer required, the opening can be glued, shrink-wrapped, or otherwise secured and resealed. In contrast, the binding yarn may require a full cut to gain access to the twisting elements in order to release tension in the binding yarn.

Claims (38)

1. an optical communication cable, described optical communication cable comprises:

(A) core of described cable, described core comprises:

(i) optical fiber, described optical fiber comprise separately the core that surrounds by covering;

(ii) separator tube, described separator tube surrounds the subset of described optical fiber,

(iii) central strength member, wherein said separator tube carries out stranded around described central strength member with the stranded pattern comprising reverse on the laying direction of described separator tube;

(B) armor, described armor surrounds described core, and wherein said armor comprises metal; And

(C) sheath, described sheath surrounds and is bonded to described armor, and wherein said sheath comprises polymkeric substance;

(D) to tie film, described in film of tying described separator tube is remained in appropriate location around described central strength member,

Wherein said film of tying surrounds described core and is in described armor inside,

It is inner that wherein said film of tying is bonded to described armor, provides the fast approaching to described core thus by film of tying described in removing while described armor and sheath being removed.

2. optical communication cable according to claim 1, is characterized in that, described in film of tying comprise polymkeric substance as its principal ingredient.

3. optical communication cable according to claim 2, is characterized in that, described in the tie described polymkeric substance of film be tygon or polypropylene, and the described polymkeric substance of wherein said sheath is tygon.

4. optical communication cable according to any one of claim 1 to 3, it is characterized in that, described film of tying is continuous print in the circumference around described core element, thus when from during cross-sectional view formed continuous closed-circuit, and be continuous print in the longitudinal direction along described cable length, described length is at least 10 meters.

5. optical communication cable according to any one of claim 1 to 4, is characterized in that, on average, and thickness at least five times of tying described in described sheath ratio.

6. optical communication cable according to any one of claim 1 to 5, it is characterized in that, described film of tying has outside surface and described armor has inside surface, and the described outside surface of thing of wherein tying is bonded to the described inside surface of armor layer by least one in glue, cementing agent and chemical adhesion.

7. optical communication cable according to any one of claim 1 to 6, it comprises further:

(E) absorb water powder particle, tie on the inside surface of film described in described water suction powder particle is positioned at, be in described in tie between film and described core.

8. optical communication cable according to claim 7, is characterized in that, film of tying described at least some in described powder particle is partly embedded, make a part for described powder particle submerge described in tie film, and its another part exposes.

9. optical communication cable according to any one of claim 1 to 8, is characterized in that, described sheath is bonded to described armor, and described bonding is facilitated by Chemical Felter, and wherein said armor comprises the corrugated metal sheet with lateral edge.

10. optical communication cable according to claim 9, is characterized in that, described sheath comprises:

(i) major part, described major part is formed by the first material and comprises inside surface and outside surface; And

(ii) close to feature, described is formed by the second material and be embedded in described major part close to feature, wherein said overlapping with the described lateral edge of described armor close in feature.

11. 1 kinds of optical communication cables, described optical communication cable comprises:

(A) core of described cable, described core comprises core element, and described core element comprises one or more optical fiber;

(B) armor, described armor surrounds described core, described armor comprises two or more independent armor pieces, each independent armor piece has and to be engaged to another in described independent armor piece in corresponding interface to combine described independent armor piece and to form the lateral edge of described armor, the described lateral edge of engaged independent armor piece to be placed together less than whole degree of freedom, makes described corresponding independent armor piece tangentially to pull open each other and away from bearing by wherein said interface; And

(C) sheath, described sheath surrounds described armor, and described independent armor piece keeps together by wherein said sheath, and described sheath comprises:

(i) major part, described major part is formed by the first material and comprises inside surface and outside surface; And

(ii) secondary part, described secondary part is formed by the second material and is embedded in described major part, wherein said secondary part overlays on the described interface of described independent armor piece respectively, and wherein said secondary part relaxes tears with the formula of zipping that described corresponding interface phase associates, and support that single step mode core is close by facilitating described sheath to tear around described interface when described independent armor piece tangentially pulls open each other.

12. optical communication cables according to claim 11, is characterized in that, the described major part of described sheath is tightly bonded to described armor, and described bonding is facilitated by Chemical Felter.

13. optical communication cables according to claim 11 or 12, it is characterized in that, described independent armor piece is two parts, and on described two part opposition sides, only there are two interfaces at the lateral edge place that connects of described two parts, the bearing that one in wherein said independent armor piece each place be deformed in described two interfaces is provided for another independent armor piece is crimped on together in described interface to make described two independent armor pieces.

14. according to claim 11 to the optical communication cable according to any one of 13, it is characterized in that, described core comprises central strength member further, wherein said core element comprises the separator tube of the subset of surrounding one or more optical fiber described, and wherein said separator tube carries out stranded around described central strength member with the stranded pattern comprising reverse on the laying direction of described separator tube.

15. according to claim 11 to the optical communication cable according to any one of 14, and it comprises further:

(D) to tie film, described in film of tying surround the described core being in described armor inside, wherein on average, thickness at least five times of tying described in described sheath ratio.

16. optical communication cables according to claim 15, it is characterized in that, described film of tying is continuous print in the circumference around described core element, thus when from during cross-sectional view formed continuous closed-circuit, and be continuous print in the longitudinal direction of the length along described cable, described length is at least 10 meters.

17. optical communication cables according to claim 15 or 16, it comprises further:

(E) absorb water powder particle, tie on the inside surface of film described in described water suction powder particle is positioned at, be in described in tie between film and described core element, to tie described at least some in wherein said powder particle is partly embedded film, make a part for described powder particle submerge described in tie film, and its another part exposes.

18. according to claim 15 to the optical communication cable according to any one of 17, it is characterized in that, it is inner that described film of tying is bonded to described armor, provides the fast approaching to described core thus by film of tying described in removing while described armor and sheath being removed.

19. 1 kinds of optical communication cables, described optical communication cable comprises:

Sheath, described sheath is formed by extruding the first material and comprise the inside surface limiting passage;

Multiple optical transmission components, described optical transmission components is positioned in described passage;

To tie film, described in film of tying be formed by extruding the second material and comprise outside surface, wherein said film of tying surrounds described multiple optical transmission components; And

Armor layer, described armor layer to be positioned in described passage and to surround described multiple optical transmission components, and film of tying described in surrounding, and the described outside surface of wherein said film of tying is bonded to the inside surface of described armor layer.

20. optical communication cables according to claim 19, is characterized in that, the outside surface of described armor layer is bonded to the described inside surface of described sheath.

21. optical communication cables according to claim 20, it is characterized in that, described multiple optical transmission components is tied together by described film of tying, and wherein said tie described bonding between film and described armor layer and described bonding the between described armor layer and described sheath allow the individual part via opening described sheath, described armor layer and described film of tying to come close to described optical transmission components.

22. according to claim 19 to the optical communication cable according to any one of 21, it comprises the first elongate member embedded in described sheath and the second elongate member embedded in described sheath further, wherein said first elongate member and described second elongate member facilitate to described sheath tear contribute to the described multiple optical transmission components close to being positioned at described passage.

23., according to claim 19 to the optical communication cable according to any one of 22, is characterized in that, described in the tie average thickness of film be less than 1/5th of the average thickness of described sheath.

24. according to claim 19 to the optical communication cable according to any one of 23, it comprises the material water-proof material particle of tying in film described in embedding further, wherein said first material of extruding is polythene material, wherein said second material of extruding is at least one in polythene material and polypropylene material, and described armor layer is undulatory metal material.

25. according to claim 19 to the optical communication cable according to any one of 24, it is characterized in that, at least one in described multiple optical transmission components comprises the optical fiber being buffered pipe and surrounding, wherein said film of tying comprises inside surface, and described in the tie described inside surface of film directly contact the outside surface of described separator tube.

26. according to claim 19 to the optical communication cable according to any one of 25, it is characterized in that, described film of tying is continuous print in the circumference around described multiple optical transmission components, thus when forming continuous closed-circuit from during cross-sectional view perpendicular to described cable major axis, and in the longitudinal direction of the length along described cable at least 10 meters are continuous print.

27. according to claim 19 to the optical communication cable according to any one of 26, and it comprises the central strength member being positioned at described passage further, and wherein said multiple optical transmission components wraps up described central strength member with the stranded pattern of S-Z.

28. according to claim 19 to the optical communication cable according to any one of 27, it is characterized in that, described in film of tying be formed by the polymeric material with 3 lucky handkerchiefs or less Young modulus, wherein said film of tying has the thickness being less than 0.5mm.

29., according to claim 19 to the optical communication cable according to any one of 28, is characterized in that, described in film of tying be bonded to described armor by cementing agent.

30. 1 kinds of optical communication cables, described optical communication cable comprises:

Supporting member;

Multiple optical transmission components, described optical transmission components wraps up described supporting member;

To tie film, described in film of tying surround described supporting member and surround described multiple optical transmission components;

Armor, described armor wraps up described supporting member, described multiple optical transmission components and described film of tying; And

Sheath, described sheath comprises inside surface and outside surface, and described outside surface limits described sheath outside and described inside surface limits passage;

Wherein said supporting member, described multiple optical transmission components, described in tie film and described armor be positioned in described passage;

Wherein said film of tying is used for described multiple optical transmission components to tie together around described supporting member; And

Wherein said film of tying is coupled to described armor, and tie described in making film and described armor are configured to be opened by single tearing together with action.

31. optical communication cables according to claim 30, it is characterized in that, described film of tying is continuous print in the circumference around described multiple optical transmission components, thus when forming continuous closed-circuit from during cross-sectional view perpendicular to described multiple optical transmission components major axis, and further, wherein said tie film in the longitudinal direction of the length along described cable at least 10 meters are continuous print, wherein said armor is bonded to described sheath, and film of tying described in making, armor and sheath are configured to be opened by single tearing together with action.

32., according to claim 30 or optical communication cable according to claim 31, is characterized in that, described in the tie thickness of film be less than 1/5th of the thickness of described sheath.

33. optical communication cables according to any one of claim 30 to 32, it is characterized in that, described armor comprises the first lateral edge and contrary second lateral edge, and described armor wraps up described supporting member, described multiple optical transmission components and described film of tying, make overlapping described second lateral edge of described first lateral edge, thus form lap.

34. optical communication cables according to claim 33, it is characterized in that, described sheath comprises the major part formed by the first extruded material and the secondary part formed by the second extruded material embedded in described first extruded material, and wherein said second extruded material is aimed at the described lap of described armor in radial directions.

35. optical communication cables according to claim 34, it is characterized in that, the elastic modulus of described first extruded material is between 100MPa and 800MPa, and the elastic modulus of described second extruded material is not more than the half of the described elastic modulus of described first material.

36. 1 kinds of optical communication cables, described optical communication cable comprises:

Sheath, described sheath is formed by extruding the first material and comprise the inside surface limiting passage;

Multiple optical transmission components, described optical transmission components is positioned in described passage;

To tie film, described in film of tying be formed by the second material of extruding being different from described first material and comprised outside surface, wherein said film of tying surrounds described multiple optical transmission components; And

Armor layer, described armor layer surrounds described multiple optical transmission components and the film be positioned at described passage of tying described in surrounding, the described outside surface of wherein said film of tying is bonded to the inside surface of described armor layer, and the outside surface of described armor layer is bonded to the described inside surface of described sheath.

37. optical communication cables according to claim 36, it is characterized in that, described film of tying is continuous print in the circumference around described multiple optical transmission components, thus when forming continuous closed-circuit from during the cross-sectional view of the major axis perpendicular to described multiple optical transmission components, wherein said tie film in the longitudinal direction of the length along described cable at least 10 meters are continuous print, the thickness of wherein said film of tying is less than 1/5th of the thickness of described sheath.

38. according to claim 36 or optical communication cable according to claim 37, it is characterized in that, described armor layer comprises the first lateral edge and contrary second lateral edge, and described armor layer wraps up described multiple optical transmission components and film of tying described in parcel, make overlapping described second lateral edge of described first lateral edge, thus formation lap, wherein said sheath comprises extruding described in embedding extrudes the elongated portion that the second material formed in the first material, wherein said elongated portion is aimed at the described lap of described armor in radial directions.